Pneumocystis jiroveci is an important cause of pneumonia (PCP) in immunocompromised individuals. The standard approach for diagnosing PCP is a microscopic examination of smears prepared from induced sputum or bronchial alveolar lavage (BAL) samples. We have also developed a rapid, quantitative PCR (polymerase chain reaction) assay for the detection of P. jiroveci in respiratory samples. Because the PCR assay is more sensitive that microscopic examination, we have demonstrated the P. jiroveci can be detected in noninvasive specimens such as oral washes. Additionally, the test can detect patient who are only colonized or have sub-clinical infections. [unreadable] [unreadable] A collaborative study with the University of California at San Francisco (UCSF) is underway to attempt to detect P. jiroveci colonization of the upper airways of healthcare workers after exposure to patients with PCP. Oral wash specimens have been collected from 60 healthcare workers and will be processed by PCR for P. jiroveci. The results of this study will define the incidence of asymptomatic colonization with this important pathogen. [unreadable] [unreadable] A second study has been initiated with collaborators at San Francisco General Hospital and Mulago Hospital workers in Uganda. Oral washes have been collected from patients with respiratory diseases who present with respiratory diseases at the hospital Tuberculosis Clinic. These specimens have been processed for mycobacterial infections (i.e., acid-fast smear and culture of the specimen) [unreadable] A new study was begun in collaboration with the San Francisco General Hospital, NIH Clinical Center CCM coworkers, and Mulago Hospital workers in Uganda to collect specimens from patients with respiratory diseases to determine if Pneumocystis jiroveci can be detected in oral washes. Specimens have been sent to the NIH for studies using the MSG Pneumocystis PCR system. Over 100 samples have been received to date.